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The most common type of error when generating a snapshot is to ignore rule 3 and/or 4. For example, it is reasonable to want to filter a view so that only active components are included. However, if you apply that filter in a way that restricts the substrate from which the snapshot is generated you will get incorrect results in which all components appear to be active even after they have been inactivated. An example of this error is shown on 

Caption label
CapId full-eg CapType Table
Full Release as at 2019-01-31

The following query when applied to the full release data shown in 

Caption reference
CapRefId full-eg CapRefType Table

 generates the erroneous snapshot view shown in 

Caption reference
CapRefId snap-err CapRefType Table

.  This query excludes inactive rows at the same time as identifying the most recent effectiveTime. The result is that components A and B are shown as active because the later rows that inactivated those components were excluded.

Code Block
Select * from `component` `c` where `c`.`effectiveTime`=(Select max(effectiveTime) from `component` where `id`=`c`.`id` and active=1)

Caption label
CapId snap-err CapType Table
Erroneous Snapshot view as at 2019-01-31

The following query when applied to the full release data shown in 

Caption reference
CapRefId full-eg CapRefType Table

 generates the correct snapshot view shown in 

Caption reference
CapRefId snap-ok CapRefType Table

. The most recent versions of all the components A-E are included. In the case of components A and B these are both inactive.

Code Block
Select * from `component` `c` where `c`.`effectiveTime`=(Select max(effectiveTime) from `component` where `id`=`c`.`id`)

Caption label
CapId snap-ok CapType Table
Erroneous Snapshot view as at 2019-01-31

The following query when applied to the full release data shown in 

Caption reference
CapRefId full-eg CapRefType Table

 generates the correct snapshot view shown in 

Caption reference
CapRefId snap-active CapRefType Table

 with inactive rows filtered out after generating the snapshot view. Only components C-E are included as the most recent versions of components A and B are inactive.

Code Block
Select * from `component` `c` where `c`.`active`=1 and `c`.`effectiveTime`=(Select max(effectiveTime) from `component` where `id`=`c`.`id`)

Caption label
CapId snap-ok CapType Table
Correct Snapshot view as at 2019-01-31 with inactive rows excluded